Exxon Mobil, Refiners Seek
Review in Unocal Patent Case

Exxon Mobil Corp. said it and four other refiners asked the U.S. Supreme Court to review a lower court ruling validating Unocal Corp.'s patent covering low-emissions gasoline formulations.

The ruling required Exxon Mobil, Irving, Texas, and other refiners to pay Unocal royalties on a patent covering the production of clean-burning gasoline in California. With the introduction of a new federally required lower-emissions gasoline...